The ISS Progress 21 cargo spacecraft, which launched from the Baikonur Cosmodrome in Kazakhstan on Monday, docked at the station Wednesday. The ship was the first supply shipment for Expedition 13 Commander Pavel Vinogradov and Flight Engineer Jeff Williams, who have been in space for almost a month.
The spacecraft brought fresh fruit and other foods, gifts from home, fuel, water, oxygen, spare parts and science gear. Two Progress cargo craft are now docked at the complex. Oxygen supplies from ISS Progress 20, which arrived in December, continue to be used to replenish the cabin air when required. The crew is loading that Progress with trash and unneeded equipment. The spacecraft will be jettisoned from the complex in mid-June.
Early in the week, Williams replaced a Remote Power Control Module, a type of circuit breaker, in the station's Destiny laboratory. The power control module had not been functioning for some time, and electricity for many lab systems had been delivered via an alternate path. To gain access to the worksite for replacement of the component, Williams had to disassemble and remove his sleeping compartment. Mission Control sequentially powered off many lab systems and lights to facilitate the replacement. Williams accomplished all the work ahead of schedule, and the new power control module has been functioning well.
Science activities aboard the station during the past week included work by Williams with the Capillary Flow Experiment, which is an investigation of fluid behavior in weightlessness that may assist in the design of future spacecraft. The crew members also completed urine collection and notes about their food consumption for an experiment studying the formation of kidney stones in weightlessness.
Vinogradov completed routine maintenance of the station's Elektron system. It was powered off much of the week and reactivated today. The Elektron provides oxygen for the cabin air from water.
Plans for next week include an engine firing to boost the station's altitude on Thursday, May 4; continued unloading of the newly arrived Progress vehicle; and periodic crew health checks.